It is known that Vero cells, a monkey kidney epithelial cell line, is deficient for Interferon production [19]; thus, this cytokine group well known

to be capable of inducing in vitro persistence click here in Chlamydia pneumoniae [1], cannot be Selumetinib mw relevant for our co-infection persistence model. Co-infection experiments with ca-PEDV are best performed with Vero cells, as they have been shown to be permissive for viral replication in contrast to other cell lines such as PD5, PK 15, and HRT18 cell lines [9]. Specific measurements of primate cytokines in our co-infection model are planned in the future to elucidate the mechanism leading to chlamydial persistence. The Herpes simplex virus (HSV) co-induced Chlamydia trachomatis persistence model [15] has been recently been shown not to be mediated by any known persistence inducer or anti-chlamydial pathway recently [20, 21]. Instead, it was hypothesized by the authors that HSV-2 attachment and/or entry into the host cell is sufficient for stimulating chlamydial persistence, suggesting a potential novel

host signaling pathway could be responsible for inducing chlamydial persistence. A very recent publication by the same group showed that HSV replication is not necessary for persistence induction and that chlamydial activity could be recovered after co-infection with UV-inactivated HSV-2. Finally, it was concluded AP24534 in vivo that the interaction of HSV glycoprotein D with the host cell surface is crucial to trigger chlamydial persistence [22]. Female genital tract infection often has a complex etiology, where Chlamydia trachomatis is present together ID-8 with one or more genital agents. Epidemiological and clinical studies have shown that double infection with HSV-2 and Chlamydia trachomatis occurs in vivo; thus, the in vitro model described by Deka et al. (2006) [15] represents a realistic situation in human medicine. Similarities exist to the in vitro model established in this study as simultaneous intestinal infection with different pathogens is possible in swine in vivo. A recent

study [23] documented the occurrence of aberrant chlamydial bodies in vivo in intestinal tissues of pigs. In this study, aberrant bodies of Chlamydia suis were demonstrated and characterized in the gut of pigs experimentally infected with Salmonella typhimurium by transmission electron microscopy. It was concluded by Pospischil et al. [23] that aberrant bodies occur in vivo in pigs and that the gnotobiotic pig model might be suitable for the study of chlamydial persistence in vivo. Available intestinal tissues from experimentally infected gnotobiotic piglets (single infection and co-infection with Chlamydia and ca-PEDV, respectively) will be investigated in the future with the aim of further characterization of ABs in vivo.